Fears raised over stem rust risk to UK wheat crop

UK wheat may be at renewed risk from stem rust – a disease associated with crop failure and famine – according to a new study.

Stem rust had not been seen in the UK for more than 60 years until 2013, when a single wheat plant in Suffolk was found to be infected.

The discovery prompted a study by researchers from the John Innes Centre in Norwich, who learned that the strain of stem rust responsible for the infection in Suffolk belonged to the Digalu race of the fungus, which also caused outbreaks in Ethiopia, Sweden, Denmark and Germany in 2013.

The researchers have now warned that wheat and barley crops could be under threat from a “perfect storm of conditions” that could encourage a resurgence in stem rust, adding that over 80% of UK wheat varieties tested were susceptible to this strain of the pathogen.

In addition to climate changes that could help the fungus grow, increased plantings of Barberry bushes have added to the risk of steam rust, according to the study.

The Barberry shrub had largely disappeared from England last century after farmers noticed that cereal crops grown next to Barberry bushes were at greater risk of stem rust. However, in the past 20 years, Barberry has been replanted in a bid to conserve the endangered Barberry Carpet moth.

Dr Diane Saunders, lead author of the study Potential for re-emergence of wheat stem rust in the United Kingdom, said: “Replanting Barberry in woodlands, gardens and areas away from arable land would ensure we provide a vital habitat for the endangered Barberry Carpet moth, while limiting its potential impact on enhancing rust pathogen diversity.”

Although milling industry insiders have said there is unlikely to be any immediate threat to UK production from stem rust, the study also urged the re-initiation of resistance breeding of crops.

Mark Parsons, of Butterfly Conservation, said the charity was working with the John Innes Centre to minimise the potential risk from stem rust while increasing the chances of survival for the Barberry Carpet moth.

“We are very concerned about the potential risk from the possible re-establishment of stem rust in this country and the impact it could have on agriculture and the environment,” he added.